The plan was for the Galaxy class to have a projected lifespan of 100 years, with major swap outs to core systems (computer cores, power systems, warp nacelles) every 20 years, while internal modules were upgraded/replaced as needed and available.

We know during the TNG run the Enterprise received everything from shield, phaser array and warp core replacement.

It's very, VERY inconsistent. The TOS/classic movie Enterprise was due to be retired after 20 years (STIII). Enterprise NX-01 after a mere ten (ENT: TATV).

Then we get ships like the Hathaway, which is still spaceworthy and being used for training exercises after 80 years. We saw a heavily damaged NX-01 last 100+ years in an alternate timeline in "E2"

The Klingon D7/K'tinga design has been used for at least 225 years (first appearance: ENT: "Unexpected" in 2151, seen throughout TOS, TNG and DS9) and the Bird of Prey for almost as long. Although I don't know how long each individual ship is supposed to last. Their rusty, worn out appearance suggests they're very old.

I'd imagine space faring species that have been out there a long time tend to use ship designs for a long, long time, especially if the level of technology had been somewhat stagnant. Vulcans, Andorians, Klingons, were all very long interstellar species before humanity, so their designs probably have a lot more longevity. (You wouldn't be surprised to see a D'kyr wandering around in the 24th century, for example)

For example some background Material says the 1701 was launched in 2245 with planed reteriment circa 2285 (TSFS).

I guess it might depend on the class of ship, for example the Miranda might have had a 40 year planned lifespan, whilst the Excelsior might have had an 80 year planned lifespance because of the additional resources needed for it's construction.

One thing I often read to determine how long a ship is used in Star Trek seems to be hull life, but I think from somewhere in the TNG-era on that's not a problem anymore.
Consider how often Voyager was heavily damaged and in the next episode (maybe a few weeks later?) she was like new. I tend to think they just can repair almost everything with replicators and similar tech, and with that I mean the possibility to manipulate matter on the atomic level. Imagine bending a metal rod so long until it breaks. As I understand it, that's because of the structure of the metal changing. If Starfleet can manipulate the structure of the materials they use, they could repair anything indefinately.

Although I know that in Voyager it probably was just lazy storywriting. ^^

The Klingon D7/K'tinga design has been used for at least 225 years (first appearance: ENT: "Unexpected" in 2151, seen throughout TOS, TNG and DS9) and the Bird of Prey for almost as long. Although I don't know how long each individual ship is supposed to last. Their rusty, worn out appearance suggests they're very old.

Click to expand...

Indeed, however "design" doesn't mean "ship".

On other notes. As was said before the USS Enterprise(CVN65) was in service for 50 years. Had there been more Enterprise-class ships I don't think she would have been retired.

Also, the USAF B-52 Stratofortress line is STILL in service after more then 60 years. The plan is to keep them going to at least 2045. Thats 90+ years of active service.

The Klingon D7/K'tinga design has been used for at least 225 years (first appearance: ENT: "Unexpected" in 2151, seen throughout TOS, TNG and DS9) and the Bird of Prey for almost as long. Although I don't know how long each individual ship is supposed to last. Their rusty, worn out appearance suggests they're very old.

Click to expand...

Indeed, however "design" doesn't mean "ship".

Click to expand...

I always felt that the life of a particular starship design didn't always match up with the life of a particular vessel.

The Galaxy-class may have a design life of 100 years--and maybe one or two of those ships may come close to that--but other ships in that design may be retired far earlier depending on individual circumstances. In "All Good Things...", the Enterprise-D was going to be decommissioned after less than 25 years of service. Conversely, it's possible that the NX-class continued for many decades after NX-01 Enterprise was decommissioned, and her retirement had nothing to do with the design, IMO.

It's very, VERY inconsistent. The TOS/classic movie Enterprise was due to be retired after 20 years (STIII).

Click to expand...

And yet when that ill-nformed and badly written admiral said that, the E was already actually 40 years old.

Click to expand...

Maybe Admiral Morrow grew up on Mars so he just slipped up and was talking his native Martian years...

Yeah, the 20 years line was because TOS aired 20 years before the release of TSFS. In-universe it doesn't add up. If we discard all backstage materials, and just use on-screen evidence, a 20 year old Enterprise still has problems. In TWOK, Kirk claims that he hadn't seen Khan in 15 years. TSFS seems to follow right on the heels of TWOK so, given Morrow's 20 year line, that would make Enterprise 5 years old during the first season at the time of "Space Seed." But that doesn't add up, because in "The Menagerie" we learn the Spock served with Pike aboard Enterprise for 11 years. If we assume Kirk took over from Pike less than a year before "Space Seed," that still would make the ship at least 26 years old, by the time of TSFS.

On the other hand, Decker claimed that "this is almost a totally new Enterprise" in TMP. But if TSFS is set 20 years after TMP, then those guys aged remarkably well... And that would push back the date of TSFS. In Voyager we learn that the five-year mission ended in 2270. Seems like some line in TMP made it seem like the refit took two and half years. Let's say 2273. Add twenty years and now TSFS takes place in 2293.

However, maybe a 2293 date would make Kirk's reaction to vintage 2283 Romulan ale more understandable...

I think Morrow's 20-year line is a case of "real-world time" trumping "in-universe time." One can either substitute 40 for 20, or just chalk it up to Morrow not really knowing how old the Enterprise actually was, but knew she was at least 20 and Starfleet wasn't going to devote any more of its resources keeping an aging cadet vessel operational.

It's very, VERY inconsistent. The TOS/classic movie Enterprise was due to be retired after 20 years (STIII).

Click to expand...

And yet when that ill-nformed and badly written admiral said that, the E was already actually 40 years old.

Click to expand...

Maybe Admiral Morrow grew up on Mars so he just slipped up and was talking his native Martian years...

Yeah, the 20 years line was because TOS aired 20 years before the release of TSFS. In-universe it doesn't add up. If we discard all backstage materials, and just use on-screen evidence, a 20 year old Enterprise still has problems. In TWOK, Kirk claims that he hadn't seen Khan in 15 years. TSFS seems to follow right on the heels of TWOK so, given Morrow's 20 year line, that would make Enterprise 5 years old during the first season at the time of "Space Seed." But that doesn't add up, because in "The Menagerie" we learn the Spock served with Pike aboard Enterprise for 11 years. If we assume Kirk took over from Pike less than a year before "Space Seed," that still would make the ship at least 26 years old, by the time of TSFS.

On the other hand, Decker claimed that "this is almost a totally new Enterprise" in TMP. But if TSFS is set 20 years after TMP, then those guys aged remarkably well... And that would push back the date of TSFS. In Voyager we learn that the five-year mission ended in 2270. Seems like some line in TMP made it seem like the refit took two and half years. Let's say 2273. Add twenty years and now TSFS takes place in 2293.

However, maybe a 2293 date would make Kirk's reaction to vintage 2283 Romulan ale more understandable...

--Alex

Click to expand...

I have no issues with the Enterprise being 40 years old in TSFS. We are forgetting Capt. April. Captain of the Enterprise before Pike.